Torque sensor

Abstract

A torque sensor includes a first region, a second region, a plurality of third regions connecting the first and second regions, a first strain generation part and a second strain generation part. The first strain generation part of which a first end is provided on the first region, and of which a first intermediate portion is provided on a second structure. The second strain generation part of which a third end is provided on the first region, of which a second intermediate portion is provided on the second region, and of which a fourth end is provided near a second end of the first strain generation part. A strain body provided with a resistor connects the second end of the first strain generation part and the fourth end of the second strain generation part.

What is claimed is: 
     
       1. A torque sensor including a first region, a second region, and a plurality of third regions connecting the first region and the second region, a torque to be measured being transmitted between the first region and the second region via the third regions, the torque sensor comprising:
 a first strain generation part comprising a first end, a second end, and a first intermediate portion between the first end and the second end, the first end being provided on the first region, the first intermediate portion being provided on the second region; 
 a second strain generation part comprising a third end, a fourth end, and a second intermediate portion between the third end and the fourth end, the third end being provided on the first region, the second intermediate portion being provided on the second region, the fourth end being opposed and spaced apart from the second end of the first strain generation part; and 
 a strain body connecting the second end of the first strain generation part and the fourth end of the second strain generation part and being provided with a resistor. 
 
     
     
       2. The torque sensor of  claim 1 , wherein
 in the first strain generation part, a length between the first intermediate portion and the second end is longer than a length between the first intermediate portion and the first end and, in the second strain generation part, a length between the second intermediate portion and the fourth end is longer than a length between the second intermediate portion and the third end. 
 
     
     
       3. The torque sensor of  claim 1 , wherein
 the first strain generation part and the second strain generation part are arranged at positions symmetrical with respect to a center of action of the torque in the first region and the second region, and the strain body is arranged at a center of action of the torque in the first region and the second region. 
 
     
     
       4. The torque sensor of  claim 1 , wherein
 the strain body comprises a bridge circuit including a plurality of strain gauges. 
 
     
     
       5. The torque sensor of  claim 1 , wherein
 widths of parts of the first region and the second region, which connect to the third regions, are larger than widths of parts connected to the first strain generation part and the second strain generation part. 
 
     
     
       6. The torque sensor of  claim 1 , wherein
 widths of parts of the first region and the second region, which connect to the third regions, are equal to widths of parts connected to the first strain generation part and the second strain generation part.